Batch kinetic studies in phenol biodegradation and comparison

Abstract

Pure cultures of <i style="">pseudomonas putida</i>, <i style="">Nocardia</i> sp., <i style="">Bacillus</i> <i style="">circulans</i> and a mixed culture, isolated from mangrove forest soil, were used to study phenol biodegradation in the batch reactor. The aim was to determine the kinetics of phenol biodegradation by measuring the biomass growth rates and phenol concentration as a function of time in a batch reactor. The kinetic constants, specific growth rate (<img src='/image/spc_char/micro.gif'> _m), inhibition coefficient for phenol (K_i) and half saturation coefficient for phenol (K_s) were determined using the Haldene equation [<img src='/image/spc_char/micro.gif'> _ms/(K_s + S + (S²/K_i)]. The values obtained for kinetic constants are in the range of those published in literature for pure and mixed cultures degrading phenol. The length of the lag phase before the exponential growth phase increases linearly with phenol concentration. As compared to others, <i style="">p. putida</i> has the maximum specific growth rate both in the present study as well as in literature. Thus, selecting a pure culture of <i style="">p. putida</i> for phenol degradation could lead to higher efficiencies.